Reamer / guide interchangeable tubular shoe

ABSTRACT

An interchangeable casing shoe for a wellbore is disclosed. The interchangeable casing shoe includes a cylindrical housing, a first engagement assembly mounted to an outer diameter of the cylindrical housing and selectively extendible between a recessed position and an extended position, and a second engagement assembly mounted within the cylindrical housing and configured to engage a running tool. The wellbore has a wellbore tubular having an internal diameter surface. When in the extended position, the first engagement assembly engages the internal diameter surface of the wellbore tubular. When deployed at depth in the wellbore, the running tool engages the second engagement assembly and selectively shifts the first engagement assembly into the recessed position releasing the casing shoe.

BACKGROUND

Hydrocarbon resources are typically located below the earth's surface in subterranean porous rock formations, often called reservoirs. These hydrocarbon bearing reservoirs can be found in depths of tens of thousands of feet below the surface. In order to extract the hydrocarbon fluids, also referred to as oil and/or gas, wells may be drilled to gain access to the reservoirs. Wells may be drilled vertically from surface, deviated from vertical, or vertical to horizontal in order to most effectively and efficiently access the subsurface hydrocarbon reservoirs.

A step in the drilling operations, or well construction, involves casing the wellbore with tubulars and cementing the tubulars in place. This isolates the internal conduit or well from the surrounding formations, which may be prone to collapse or have undesirable hazards present such as shallow gas. Each section of the well is typically drilled with a drill bit that is attached to a length of drill string that extends from the bottom of the wellbore to the drilling rig at surface. Upon the completion of drilling a section of well bore, the drilling string and drill bit are pulled out of the wellbore and a section of casing is deployed into the wellbore, which will be cemented into place creating the desired isolation from the newly drilled formation. However, depending on the depth of the wellbore there is a period time between removing the drilling string/drill bit and rigging up and deploying the casing. During this time period the newly drilled formation is left open and is referred to as an ‘open hole’. The open hole section, depending on the makeup of the formation surrounding it, maybe be prone to stability risks, which can be time consuming and expensive to remedy.

SUMMARY

This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

In one aspect, embodiments disclosed herein relate to interchanging a casing shoe while the casing is deployed downhole in a wellbore. The casing shoe has cylindrical housing shaped body, a first engagement assembly on the circumferential outer diameter of the cylindrical body for engaging the internal surface of the wellbore casing, and a second engagement assembly mounted within the cylindrical body for engaging a running tool. When deployed inside the inner diameter of the wellbore tubular, the running tool engages the first engagement assembly of the casing shoe, and selectively shifts the second engagement assembly from the extended position to the recessed position, releasing the casing shoe from the internal diameter surface of the wellbore tubular.

The casing shoe can be either a guide shoe, a reamer shoe, or equivalent. In addition, either the guide shoe or the reamer shoe can be initially deployed on the first joint of casing. The requirement to change out the casing shoe is typically dictated by the wellbore conditions, which include scenarios where there are restrictions or tight spots present in the wellbore open hole section. These conditions may be created by poor wellbore circulation causing drilling cuttings to build up or wellbore stability issues related to reactive formations resulting in a partial collapse of the wellbore.

In one or more embodiments, the guide shoe may need to be interchanged with a reamer shoe to address a restriction in the wellbore. In this scenario, while the casing remains in the wellbore, a running tool is deployed into the wellbore through the internal diameter of the casing and engages the first engagement assembly of the guide shoe. The running tool selectively shifts the second engagement assembly into the recessed position, releasing the guide shoe from the internal diameter of the casing. The running tool, and attached guide shoe, are pulled out of the wellbore to surface. The guide shoe is changed out and a reamer shoe is installed on the running tool and deployed into the wellbore. The reamer shoe is installed on the last joint of casing in the same location as the removed guide shoe by the running tool selectively shifting the second engagement assembly of the reamer shoe to the extended position anchoring the reamer shoe to the casing. The running tool is disconnected from the reamer shoe and pulled out of the wellbore. With the reamer shoe installed, the top drive and drawworks rotate and apply weight down on the casing and reamer. There are a series of cutting blades mounted on the external surface of the reamer shoe, which cut and ream the formation creating a larger gauge hole in the wellbore open hole section. With the restriction removed the casing is conveyed deeper into the wellbore until the setting depth is reached. At this stage the reamer shoe can be changed out for a guide shoe following the same procedure described above, or the reamer shoe can remain attached to the casing while the casing is cemented in place.

In another aspect, embodiments of the present disclosure relate to a method where the reamer shoe is initially attached to the casing while the casing string is being deployed into the wellbore. In this scenario, the casing and reamer shoe are already in place to address any restriction that may be present in the wellbore permitting the casing to be deployed to the setting depth. As with the previous embodiment, the reamer shoe may be changed out for a guide shoe or the reamer shoe may remain attached to the casing while the casing is cemented in place. If the reamer shoe is to be changed out, a running tool is deployed into the wellbore through the internal diameter of the casing and engages the first engagement assembly of the reamer shoe. The running tool selectively shifts the second engagement assembly into the recessed position, releasing the reamer shoe from the internal diameter of the casing. The running tool, and attached reamer shoe, are pulled out of the wellbore to surface. The reamer shoe is changed out and a guide shoe is installed on the running tool and deployed into the wellbore. The guide shoe is installed on the last joint of casing in the same location as the removed reamer shoe by the running tool selectively shifting the second engagement assembly of the guide shoe to the extended position anchoring the guide shoe to the casing. The running tool is disconnected from the reamer shoe and pulled out of the wellbore. At this point the casing is cemented in place, and the casing running operations are complete.

Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

Specific embodiments of the disclosed technology will be described in detail with reference to the accompanying figures. Like elements in the various figures are denoted by like reference numerals for consistency. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn are not necessarily intended to convey any information regarding the actual shape of the particular elements and have been solely selected for ease of recognition in the drawing.

FIG. 1 illustrates a drilling rig and wellbore.

FIG. 2 is a schematic showing the deployment of a casing with guide shoe in accordance with one or more of the embodiments.

FIG. 3 is a schematic showing the deployment of a casing with reamer shoe in accordance with one or more of the embodiments.

FIGS. 4A-4J show schematic diagrams depicting the interchangeable reamer/guide shoe operation sequence in accordance with one or more of the embodiments.

FIG. 5 is a flowchart in accordance with one or more of the embodiments.

FIG. 6 is a flowchart in accordance with one or more of the embodiments.

DETAILED DESCRIPTION

In the following detailed description of embodiments of the disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the disclosure. However, it will be apparent to one of ordinary skill in the art that the disclosure may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

Throughout the application, ordinal numbers (e.g., first, second, third, etc.) may be used as an adjective for an element (i.e., any noun in the application). The use of ordinal numbers is not to imply or create any particular ordering of the elements nor to limit any element to being only a single element unless expressly disclosed, such as using the terms “before”, “after”, “single”, and other such terminology. Rather, the use of ordinal numbers is to distinguish between the elements. By way of an example, a first element is distinct from a second element, and the first element may encompass more than one element and succeed (or precede) the second element in an ordering of elements.

FIG. 1 illustrates an exemplary well site (100). In general, well sites may be configured in a myriad of ways. Therefore, the well site (100) is not intended to be limiting with respect to the particular configuration of the drilling equipment. The well site (100) is depicted as being on land. In other examples, the well site (100) may be offshore, and drilling may be carried out with or without use of a marine riser. A drilling operation at well site (100) may include drilling a wellbore (102) into a subsurface including various formations (126). For the purpose of drilling a new section of wellbore (102), a drill string (112) is suspended within the wellbore (102). The drill string (112) may include one or more drill pipes connected to form conduit and a bottom hole assembly (BHA) (124) disposed at the distal end of the conduit. The BHA (124) may include a drill bit (128) to cut into the subsurface rock. The BHA (124) may include measurement tools, such as measurement-while-drilling (MWD) tool and logging-while-drilling (LWD) tool (not shown), as well as other drilling tools that are not specifically shown.

The drill string (112) may be suspended in wellbore (102) by a derrick structure (101). A crown block (106) may be mounted at the top of the derrick structure (101), and a traveling block (108) may hang down from the crown block (106) by means of a cable or drilling line (103). One end of the drill line (103) may be connected to a drawworks (104), which is a reeling device that can be used to adjust the length of the cable (103) so that the traveling block (108) may move up or down the derrick structure (101). The traveling block (108) may include a hook (109) on which a top drive (110) is supported. The top drive (110) is coupled to the top of the drill string (112) and is operable to rotate the drill string (112). Alternatively, the drill string (112) may be rotated by means of a rotary table (not shown) on the surface (114). Drilling fluid (commonly called mud) (not shown) may pump the mud from the mud system (130) into the drill string (112). The mud may flow into the drill string (112) through appropriate flow paths in the top drive (110) (or a rotary swivel if a rotary table is used instead of a top drive to rotate the drill string (not shown)).

During a drilling operation at the well site (100), the drill string (112) is rotated relative to the wellbore (102), and weight is applied to the drill bit (128) to enable the drill bit (128) to break rock as the drill string (112) is rotated. In some cases, the drill bit (128) may be rotated independently with a drilling motor (not shown). In further embodiments, the drill bit (128) may be rotated using a combination of the drilling motor (not shown) and the top drive (110) (or a rotary swivel if a rotary table is used instead of a top drive to rotate the drill string (112)). While cutting rock with the drill bit (128), mud (not shown) is pumped into the drill string (112). The mud flows down the drill string (112) and exits into the bottom of the wellbore (102) through nozzles in the drill bit (128). The mud in the wellbore (102) then flows back up to the surface in an annular space between the drill string (112) and the wellbore (102) with entrained cuttings (not shown). The mud with the cuttings is returned to the mud system (130) to be circulated back again into the drill string (112). Typically, the cuttings are removed from the mud, and the mud is reconditioned as necessary, before pumping the mud again into the drill string (112).

Post drilling operations, when the drill string (112), the BHA (124), and the drill bit (128) have been removed from the wellbore (102), in some embodiments of wellbore (102) construction, the casing operations may commence. A casing string (116), which is made up of one or more lager diameter tubulars that have a larger outer diameter than the drill string (112) but a smaller outer diameter than the wellbore (102), are lowered into the wellbore (102) on the drill string (112). In some embodiments, the casing string (116) is designed to isolate the internal diameter of the wellbore (102) from the adjacent formation (126). Once the casing string (116) is in position, it is set and cement is pumped down through the internal space of the casing string (116), out of the bottom of the casing shoe (120), and fills the annular space between the wellbore (102) and the outer diameter of the casing string (116). This secures the casing string (116) in place and creates the desired isolation between the wellbore (102) and the formation (126). At this point, drilling of the next section of the wellbore (102) may commence.

Those skilled in the art will appreciate that casing is run as noted above on an equivalent size diameter tubular from bottom to surface which requires additional casing joints similar to all casing running jobs in the art.

FIG. 2 depicts, in one or more embodiments, a proposed layout of a guide shoe (200) and a casing (202). The depicted guide shoe (200) may have a rounded profile, be constructed from steel or equivalent, and is a slightly smaller diameter than the casing (202). In addition, the guide shoe (200) will consist of at least one circular port (205) near the rounded profile, which is used for fluid circulation and, if required, cementing operations. One of ordinary skill would readily appreciate that the circular port (205) configuration may also be multiple circular ports (205) or smaller diameter circular ports (205) depending on the results of the circulation hydraulic simulation. The guide shoe (200) may be fitted to the end of the first joint of casing (202) before deployment into a wellbore (102) or after the casing (202) is at depth in the wellbore (102).

In one or more embodiments, to fit or anchor the guide shoe (200) to the casing (202), a set of guide shoe slips (206) may be disposed on the outside profile of the guide shoe (200) and consist of angle ridges (214). In addition, the guide shoe (200) may have a first engagement assembly (208) disposed at the top of the cylindrical housing (204). When a running tool (406) engages the first engagement assembly (208) of the guide shoe (200), the guide shoe slips (204) may be activated to extend gripping the internal diameter surface (211) of the casing (202) anchoring the guide shoe (200) to the casing (202). In the scenario where the guide shoe (200) is fitted to the end of the casing (202) while at depth in the wellbore (102), the guide shoe (200) includes a no-go profile (210) that may be used to accurately locate the lower most end of the casing (202). The non-go profile (210) may be of a tapered design that exists on the outside profile of the guide shoe (200), such that the outside diameter of the guide shoe (200) increases towards the rounded profile end (201) of the guide shoe (200). This creates a physical stopping point for the guide shoe (200) within the casing (202) at which point the guide shoe slips (206) may be deployed.

Conversely, in one or more embodiments, the guide shoe (200) may be released from the casing (202) via deactivation of the guide shoe slips (204) by the engagement of the running tool (406) with the first engagement assembly (208).

In one or more embodiments, the guide shoe (200) may also be replaced with a float guide shoe (not shown). In this case, the casing (202) may be comprised of a float guide shoe. The float guide shoe may have a float valve (not shown) which helps in well control and possible floating of the casing. The float valve is installed to allow forward flow of fluids, but will prevent reverse flow, or u-tubing, from occurring. The float guide shoe may be bull-nosed shaped and help align the liner casing (202) into the center of the wellbore (102) to avoid hitting any ledges or washouts that exist.

FIG. 3 depicts, in one or more embodiment, a proposed layout of a reamer shoe (300) and a casing (202). The depicted reamer shoe (300) may have a rounded profile, be constructed from steel or equivalent, is a slightly smaller diameter than the casing (202), and consists of a plurality of cutting blades (313). In addition, the reamer shoe (300) will consist of at least one circular port (305) near the rounded profile, which is used for fluid circulation and, if required, cementing operations. Each application will have a defined number and size of circular ports (305) based on pump through and total flow area requirements. The reamer shoe (300) may be fitted to the end of the first joint of casing or casing (202) before deployment into a wellbore (102) or after the casing (202) is at depth in the wellbore (102).

In one or more embodiments, to fit or anchor the reamer shoe (300) to the casing (202), a set of reamer shoe slips (306) may be disposed on the outside profile of the reamer shoe (300) and consist of angle ridges (314). In addition, the reamer shoe (300) may have a first engagement assembly (308) disposed at the top of the cylindrical housing (304). When a running tool (406) engages the first engagement assembly (308) of the reamer shoe (300), the reamer shoe slips (304) may be activated to extend gripping the internal diameter surface (211) of the casing (202) anchoring the reamer shoe (300) to the casing (202). In the scenario where the reamer shoe (300) is fitted to the end of the casing (202) while at depth in the wellbore (102), the reamer shoe (300) includes a no-go profile (310) that may be used to accurately locate the lower most end of the casing (202). The non-go profile (310) may be of a tapered design that exists on the outside profile of the reamer shoe (300), such that the outside diameter of the guide shoe (200) increases towards the rounded profile end (301) of the reamer shoe (300). This creates a physical stopping point for the reamer shoe (300) within the casing (202) at which point the reamer shoe slips (306) may be deployed.

Conversely, in one or more embodiments, the reamer shoe (300) may be released from the casing (202) by deactivation of the reamer shoe slips (306) via deactivation of the reamer shoe slips (306) by the engagement of the running tool (406) with the first engagement assembly (308).

In one or more embodiments, the reamer shoe (300) may be replaced with a float reamer shoe (not shown). Therefore, the liner casing (202) may be comprised of a float reamer shoe (not shown). The float reamer shoe (not) may have a float valve (not shown) which helps in well control and possible floating of the casing. The float valve is installed to allow forward flow of fluids, but will prevent reverse flow, or u-tubing, from occurring. The float reamer shoe may also be bull-nosed shaped and help align the casing (202) into the center of the wellbore (102) to avoid hitting any ledges or washouts that exist.

While anchored to the casing (202), the reamer shoe (300) operates as a reamer (not shown) to widen or increase the gauge of the open hole section (402) of the wellbore (102). To perform this function, the top drive (110), which is connected to the casing (202), rotates the casing (202) which in turn rotates the reamer shoe (300). The cutting blades (313) on the outside diameter of the reamer shoe (300) ream or drill away small pieces of the wellbore wall (not shown) or formation (126), thus increasing the diameter of the open hole section (402). This allows for the casing (202) to reach the setting depth without getting stuck or incurring damage. Alternatively, in one or more embodiments, the reamer shoe (300) may be replaced with a turbine/motor reamer shoe (not shown). The turbine/motor reamer shoe (not shown) may comprise a turbine or motor (not shown) that is configured to be deployed downhole and, by using hydraulic power provided supplied by the drilling fluid, drive the rotation of the reamer independent of the top drive (110) and casing (202). This allows the wellbore (102) to be reamed without the need to rotate the casing (202).

FIGS. 4A-4J depict, in accordance with one or more embodiments, a series of schematics that detail the operational sequence of changing out the shoe guide (200) with a reamer shoe (300), while at depth in the wellbore (102). Specifically, FIGS. 4A-4J illustrate the various sequence of events that may occur with both guide shoes and/or reamer shoes.

FIG. 4A depicts an open hole section (402) of the wellbore (102) that has been drilled by a drill bit (128) and BHA (124), and is ready for casing operations. The guide shoe (200) is shown as fitted to the casing (202) deployed, on the drill string (116), into the open hole section (402) of the wellbore (102). In one or more embodiments, the guide shoe may encounter a tight spot (404) in the open hole section (402). In this illustration, the guide shoe (200) has encountered a tight spot (402) in the wellbore (102) and is unable to pass to reach the required setting depth for the casing (202). At this stage, the guide shoe may need to be interchanged with a reamer shoe (300) or another suitable type of shoe to continue traveling downhole and overcome the tight spot (404) encountered.

FIG. 4B depicts the installation of a running tool (406) on a slick system (408) and deploying the running tool (406) into the wellbore (102) inside the casing (202). The running tool (406) is lowered via the slick line system (408) to the depth of the guide shoe (200).

FIG. 4C shows the running tool (406) engaging the second engagement assembly (212) of the guide shoe (200). The running tool (406) contains a set of lock dogs (not shown). In one or more embodiments, when engaging the second engagement assembly (406) with a downward force, the lock dogs lock into a profile on the second engagement assembly (212).

FIG. 4D depicts the guide shoe (200) being released from the casing (202). To release the guide shoe (200), the running tool (406), which is connect to the guide shoe (200) via the second engagement assembly (212), deactivates the first engagement assembly (208) releasing the guide shoe (200) from the internal diameter surface (211) of the guide shoe (200). At this point, the guide shoe (200) is connected only to the running tool (406) and is pulled out of the wellbore (102) through the inner diameter of the casing (202) by the slick line system (408).

FIG. 4E shows the casing (202) in the wellbore (102). At this stage the slick line system (408), running tool (406), and guide shoe (200) has been recovered at the surface (114) and only the casing (202) remains in the wellbore (102).

FIG. 4F depicts the reamer shoe (300) installed on the running tool (406), which is attached to the slick line system (408). The running tool (406) engages the second engagement assembly (312). The slick line system (408) lowers the running tool (406) and reamer shoe (300) into the wellbore (102) through the inner diameter of the casing (202).

FIG. 4G depicts the reamer shoe (300) reaching the bottom of the casing (202) inside the wellbore (102). The running tool (406), which is connected to the second engagement assembly (312), activates the first engagement assembly shifting the reamer shoe slips (306) which extend radially outward providing pressure on the internal diameter surface (211) of the casing (202) and anchoring the reamer shoe (300) to the casing (202).

FIG. 4H shows the running tool (406) disengaged from the second engagement assembly (312) by applying an upward force with the running tool (406), which releases the lock dogs (not shown). At this stage the running tool (406) is pulled out of the wellbore (102) by the slick system (408).

Those skilled in the art will appreciate that using lock dogs via an upward force is only one attachment/release mechanism that may be employed by embodiments disclosed herein. Other suitable attachment or release mechanisms such as shear pins, sliding sleeves, etc., which use a downward force or another type of force may also be employed without departing from the scope disclosed herein.

FIG. 4I depicts the reaming operation to clear and widen the tight spot (404) in the open hole section (402) of the wellbore (102). With the reamer shoe (300) securely anchored to the end of the casing (202), the top drive (110) and the drawworks (104) apply weight downward and rotate the reamer shoe (300) and casing (202) relative to the wellbore (102). The cutting blades (313) of the reamer guide (300) increases the wellbore diameter by cutting away and reaming the debris and formation that had created the tight spot (404). The operation may require multiple reaming passes over the tight spot (404) before the casing (202) and reamer shoe (300) can pass and be set at the bottom of the wellbore (102).

FIG. 4J shows the casing (202) and the reamer shoe (300) being lowered to the setting location at the bottom of the wellbore (204). At this stage the casing (202) is ready to be set and cemented, isolating the surrounding reservoir/formation (126). In one or more embodiments, the reamer shoe (300) may be cemented in place with the casing (202), in which case the reamer is designed to be drilled through. Alternatively, the reamer shoe (300) may be recovered at the surface (114) for future casing (202) operations. Although the reamer shoe may be to be changed for the guide shoe before cementing, this is not required.

FIG. 5 is a flowchart depicting, in one or more embodiments, the operational sequence of interchanging the guide shoe (200) for the reamer shoe (300) when encountering a tight spot (404) in the wellbore (102). The operational sequence is comparable to that illustrated in FIG. 4. However, FIG. 4 assumes that the casing (202), which is fitted with the guide shoe (200), encounters a tight spot (404) in the open hole section (402) of the wellbore (102). In addition to the operation sequence described in FIG. 4, FIG. 5 depicts the operational sequence in an event where the guide shoe (200) does not encounter a tight spot (404) in the wellbore (102). One or more blocks in FIG. 5 may be performed using one or more components as described in FIGS. 1 through 3. While the various blocks in FIG. 5 are presented and described sequentially, one of ordinary skill in the art will appreciate that some or all of the blocks may be executed in a different order, may be combined or omitted, and some or all of the blocks may be executed in parallel and/or iteratively. Furthermore, the blocks may be performed actively or passively.

In Step 500, the open hole section (402) of the wellbore (102) is drilled by a drill bit (128) and BHA (124) and is ready for casing operations. The guide shoe (200) is fitted to the casing (202) at surface and is ready to be deployed into the wellbore (102) on the drill string (116).

In Step 502, the guide shoe (200) and the casing (202) are deployed into the wellbore (102) on the drill string (116). The guide shoe (200) exits the casing shoe (120) of the previous casing string (112) and proceeds to be lowered into the open hole section (402).

In Step 504, in accordance with one or more embodiments, a decision is made as to whether the guide shoe (200) has encountered a tight spot (404) in the open hole section (402) of the wellbore (102). Examples of a tight spot (404) may include, but are not limited to, drilling cuttings build up or a partial collapse due to reactive shales/formations, which partially close off the wellbore (102). Such scenarios prevent the guide shoe (200) and casing (202) from being further lowered into the wellbore (102). At this stage, the guide shoe may need to be interchanged with a reamer shoe or another suitable type of shoe to continue traveling downhole, and overcome the tight spot encountered. If a tight spot is not encountered, the process proceeds to Step 520.

In Step 506, the running tool (406) is installed on a slick line system (408) and deployed into the wellbore (102) inside the casing (202). The running tool (406) is lowered via the slick line system (408) to the depth of the guide shoe (200).

In Step 508, the running tool (406) engages the second engagement assembly (212) of the guide shoe (200). In one or more embodiments this may be a sliding sleeve with a set of lock dogs or other method that may be known to one skilled in the art. At this stage the guide shoe slips (206), which are disposed on the cylindrical body (204) of the guide shoe (200), are in the extended position and anchored to the internal diameter surface (211) of the casing (202). The running tool (406) deactivates the slips (206), which are then retracted into the guide shoe (200), releasing the guide shoe (200) from the casing (202).

In Step 510, the guide shoe (200), which is connected to the running tool (406) is pulled out of the wellbore (102) through the inner diameter of the casing (202) by the slick line system (408).

In Step 512, the reamer shoe (300) is installed on the running tool (406), which is attached to the slick line system (408). The running tool (406) engages the second attachment assembly (312) of the reamer shoe (300). The slick line system (408) lowers the running tool (406) and reamer shoe (300) into the wellbore (102) through the inner diameter of the casing (202).

In Step 514, the no-go profile (310) on the outer profile of the reamer shoe (300) engages the internal diameter surface (211) of the casing (202) creating a physical stop and indication feature that the reamer shoe (300) is at the setting depth in the wellbore (102). The running tool (406) activates the reamer shoe slips (304), which extend radially outward providing pressure on the internal surface of the casing (202) anchoring the reamer shoe (300) to the casing (202).

In Step 516, the running tool (406) is disengaged from the second engagement assembly (312). At this stage the running tool (406) is pulled out of the wellbore (102) by the slick line system (408).

In Step 518, the reamer shoe (300) is activated to clear and widen the tight spot (404) in the open hole section (402). With the reamer shoe (300) securely anchored to the end of the casing (202), the top drive (110) and the drawworks (104) apply weight downward and rotate the reamer shoe (300) and casing (202) relative to the wellbore (102). The cutting blades (313) of the reamer guide (300) increases the wellbore diameter by cutting away and reaming the debris and formation that is creating the tight spot (404). The operation may require multiple reaming passes over the tight spot (404) before the casing (202) and reamer shoe (300) can pass and be set at the bottom of the wellbore (102). At this stage, the tight spot (404) has been cleared. The casing (202) and the reamer shoe (300) can now pass without restriction.

In Step 520, a tight spot (404) may have been encountered and cleared or a tight spot (404) may not have been present. In either scenario, the guide shoe (200) and casing (202) are lowered into the open hole section (402) of the wellbore (102) until the guide shoe (200) reaches the bottom of the wellbore (102).

In Step 522, the casing (202) is set in place in the wellbore (102) and the cement operation commences, Specifically, cement is pumped down the internal conduit of the casing (202), out of the bottom of the casing guide shoe (200), and fills the annular space between the casing (202) and the open hole section (402). This secures the casing (202) in place and isolations the wellbore (102) from the surrounding formation (126).

In Step 524, the casing (202) is disengaged and all running tools and equipment are retrieved at the surface (114).

FIG. 6 is a flowchart depicting, in one or more embodiments, the operational sequence of interchanging the reamer shoe (300) for the guide shoe (200) at a bottom hole depth in the wellbore (102). One or more blocks in FIG. 6 may be performed using one or more components as described in FIGS. 1 through 3. While the various blocks in FIG. 6 are presented and described sequentially, one of ordinary skill in the art will appreciate that some or all of the blocks may be executed in a different order, may be combined or omitted, and some or all of the blocks may be executed in parallel and/or iteratively. Furthermore, the blocks may be performed actively or passively.

In Step 600, the open hole section (402) of the wellbore (102) has been drilled by the drill bit (128) and BHA (124) and is ready for casing operations. The reamer shoe (300) is fitted to the casing (202) at the surface (114) and is ready to be deployed into the wellbore (102) on the drill string (116).

In Step 602, the reamer shoe (300) and the casing (202) are lowered into the wellbore (102) on the drill string (116). The reamer shoe (300) exits the casing shoe (120) of the previous casing (116) and proceeds to be lowered into the open hole section (402).

In Step 604, in one or more embodiments, the reamer shoe (300) and casing (202) may not be capable of reaching the desired bottom hole depth in the wellbore (102). This may be due to encountering a tight spot (404) in the open hole section (402) of the wellbore (102). Examples of a tight spot (404) may include drilling cuttings build up or a partial collapse due to reactive shales/formations, which partially close off the wellbore (102). Such scenarios prevent the reamer shoe (300) and casing (202) from being further lowered into the wellbore (102). If a tight spot (404) were encountered, the operation sequence would proceed to Step 606. If the reamer shoe and casing (202) were able to reach the desired bottom hole depth in the wellbore (102) without restriction, then the operation sequence proceed directly to Step 610.

Step 606, in one or more embodiments, assumes that a restriction due to a tight spot (404) has been encountered in the wellbore (102). As the casing (202) is fitted with the reamer shoe (300), the reaming operations to widen the wellbore open hole section (402) can commence. With the reamer shoe (300) securely anchored to the end of the casing (202), the top drive (110) and the drawworks (104) apply weight downward and rotate the reamer shoe (300) and casing (202) relative to the wellbore (102). The cutting blades (313) of the reamer shoe (300) increases the wellbore diameter by cutting and reaming the debris and formation that is creating the tight spot (404). The operation may require multiple reaming passes over the tight spot (404) before the casing (202) and reamer shoe (300) can pass and be set at the bottom of the wellbore (102).

Step 608, in one or more embodiments, depicts the reamer shoe (300) and casing (202) as being lowered into the wellbore (102) without obstruction. This may be the result of there being a tight spot (404) that has been cleared by the reamer shoe (300) or it may be that there were no restriction encountered in the open hole section (402) of the wellbore (102). In this step the casing (202) and the reamer shoe (300) have been lowered to the setting location at the bottom of the wellbore (204). In one or more embodiments, the reamer shoe (300) may be cemented in place with the casing (202). Alternatively, the reamer shoe (300) may be recovered at surface (114) for future casing (202) operations.

In Step 610, the casing (202) with the reamer shoe (300) attached may be set and cemented, isolating the surrounding reservoir/formation (126). However, to preserve the reamer shoe (300) and save cost through the potential future use of the reamer shoe (300), before cementing the casing (202) the reamer shoe (300) may be changed out with a guide shoe (200). If the decision is made to retrieve the reamer shoe (300), the process continues to step 612, otherwise the process moves to step 624.

Step 612 depicts the installing a running tool (406) on a slick line system (408) and deploying the running tool (406) into the wellbore (102) inside the casing (202). The running tool (406) is lowered via the slick line system (408) to the depth of the reamer shoe (300).

In Step 614, the running tool (406) engages the reamer shoe (300) by applying a downward force on the second engagement assembly (312) of the reamer shoe (300). The running tool (406) contains a set of lock dogs (not shown) that when engaging the second engagement assembly (406) with a downward force, the lock dogs (not shown) lock into a profile on the second engagement assembly (312).

In Step 616, the reamer shoe (300) is released from the casing (202). Prior to the reamer shoe (300) being release, the reamer shoe slips (306), which are disposed on the cylindrical housing (304) of the reamer shoe (300), are in the extended position and anchored to the internal diameter surface (211) of the casing (202). The running tool (406) deactivates the slips (306), which are then retracted into the reamer shoe (300). The reamer shoe (300) is released from the casing (202) and pulled out of the wellbore (102) through the inner diameter of the casing (202) by the slick line system (408).

In Step 618, the running tool (406), which is connected to the slick line system (408), engages the second engagement assembly (212) of the guide shoe (200). The slick line system (408) lowers the running tool (406) and guide shoe (200) into the wellbore (102) through the inner diameter of the casing (202).

In Step 620, the no-go profile (210) on the outer profile of the guide shoe (200) engages the inner diameter edge of the casing (202) creating a physical stop and indication feature that the guide shoe (200) is at the setting depth in the wellbore (102). The running tool (406) activates the guide shoe slips (204), which extend radial outward providing pressure on the inside of the casing (202) and anchoring the guide shoe (300) to the casing (202).

In Step 622, the running tool (406) is disengaged from the second engagement assembly (212) by applying an upward force with the running tool (406), which releases the lock dogs (not shown). At this stage the running tool (406) is pulled out of the wellbore (102) by the slick system (408).

In Step 624, the casing (202) is set in place in the wellbore (102) and the cement operation commences, wherein cement is pumped down the internal conduit of the casing (102), out of the bottom of the casing guide shoe (200), and fills the annular space between the casing (202) and the open hole section (402). This secures the casing (202) in place and isolations the wellbore (102) from the surrounding formation (126).

In Step 626, the casing (202) is released and all running tools and equipment are retrieved at the surface (114).

Embodiments of the present disclosure may provide at least one of the following advantages. When the casing cannot reach the bottom of the wellbore due to a tight spot in the open hole section, the disclosure provides an option that will save time and costs associated with pulling casing that was run with a guide shoe and replacing with a reamer shoe. The casing guide shoe/reamer shoe are based on existing designs which are modified to allow for retrieval/interchangeability features. Any known running tool may be used to interchange the guide shoe for the reamer shoe or vice versa. Embodiments disclosed herein apply only to running casing and not to drilling or drill bit retrieval. Thus, rather than being applicable to drilling assembly and reamer shoe interchangeability, this disclosure focuses on guide shoe and reamer shoe interchangeability in the context of running casing.

Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function. 

What is claimed:
 1. An interchangeable casing shoe for a wellbore, comprising: a casing shoe comprising a cylindrical housing; a first engagement assembly mounted to an outer diameter of the cylindrical housing and selectively extendible between a recessed position and an extended position; a second engagement assembly mounted within the cylindrical housing and configured to engage a running tool; wherein the wellbore comprises a wellbore tubular, having an internal diameter surface; wherein when in the extended position the first engagement assembly engages the internal diameter surface of the wellbore tubular; wherein when deployed at depth in the wellbore the running tool engages the second engagement assembly and selectively shifts the first engagement assembly into the recessed position releasing the casing shoe.
 2. The interchangeable casing shoe of claim 1, wherein the casing shoe is a guide shoe comprising one of a rounded profile, a bull-nosed shape, and an eccentric shape.
 3. The interchangeable casing shoe of claim 1, wherein the casing shoe is a reamer shoe comprising one of a rounded profile, a bull-nosed shape, and an eccentric shape, with a plurality of cutting blades.
 4. The interchangeable casing shoe of claim 1, wherein the casing shoe is one selected from a group consisting of: a guide shoe and a reamer shoe, wherein the guide shoe and the reamer shoe are customized to fit the wellbore tubular.
 5. The interchangeable casing shoe of claim 2, wherein the casing shoe comprises: a float valve, wherein the float valve is installed in the guide shoe to prevent backflow of fluid and to provide access to the wellbore for placement of cement.
 6. The interchangeable casing shoe of claim 2, wherein: the guide shoe comprises of at least one a circular port, cement is pumped through the circular port and the guide shoe is cemented in place with the wellbore tubular.
 7. The interchangeable casing shoe of claim 3, wherein the reamer shoe comprises: a float valve, wherein the float valve is installed in the reamer shoe to prevent backflow of fluid and to provide access to the wellbore for placement of cement.
 8. The interchangeable casing shoe of claim 3, wherein: the reamer shoe comprises of at least one a circular port, wherein cement is pumped through the circular port and the reamer shoe is cemented in place with the wellbore tubular.
 9. The interchangeable casing shoe of claim 3, wherein the reamer shoe comprises: a motor-powered device used to rotate the reamer shoe.
 10. The interchangeable casing shoe of claim 1, wherein the cylindrical housing has a smaller outer diameter than an internal diameter of the wellbore tubular.
 11. The interchangeable casing shoe of claim 1, wherein the first engagement assembly is a no-go profile and a set of slips with a packer element.
 12. The interchangeable casing shoe of claim 1, wherein the second engagement assembly is a sliding sleeve with a set of lock dogs.
 13. The interchangeable casing shoe of claim 1, wherein: the running tool is configured to be conveyed into the wellbore through the wellbore tubular via a slick line system, and the running tool comprises an outer diameter that is smaller than a internal diameter of the wellbore tubular.
 14. The interchangeable casing shoe of claim 1, wherein: the wellbore tubular is a casing.
 15. A method of interchanging a guide shoe fitted to a wellbore tubular with a reamer shoe when dictated by conditions in a wellbore, comprising: deploying a running tool at a depth in the wellbore; engaging a second engagement assembly of the guide shoe that is connected to an internal diameter surface of a wellbore tubular; selectively shifting, by the running tool, a first engagement assembly from an extended position to a recessed position, releasing the guide shoe; retrieving the guide shoe from the wellbore and releasing the guide shoe from the running tool; fitting the running tool with the reamer shoe and deploying the running tool to the depth within the wellbore; anchoring the reamer shoe to the internal diameter surface of the wellbore tubular by shifting the first engagement assembly, via the running tool, from the recessed position to the extended position ; and disengaging, by the running tool, the first engagement assembly thereby releasing the running tool.
 16. A method of interchanging a reamer shoe fitted to a wellbore tubular, with a guide shoe while at a bottom hole depth in a wellbore, comprising: deploying a running tool at the bottom hole depth in the wellbore; engaging a second engagement assembly of the reamer shoe that is connected to an internal diameter surface of a wellbore tubular; selectively shifting, by the running tool, a first engagement assembly from an extended position to a recessed position, releasing the reamer shoe; retrieving the reamer shoe from the wellbore and releasing the reamer shoe from the running tool, fitting the running tool with a guide shoe and deploying the running tool to the bottom hole depth within the wellbore; anchoring the guide shoe to the internal diameter surface of the wellbore tubular by shifting the first engagement assembly, via the running tool, from the recessed position to the extended position; and disengaging, by the running tool, the first engagement assembly thereby releasing the running tool.
 17. The method of claim 15, wherein: the running tool is deployed by one of a slickline system, a wireline system, a coil tubing system, or a drill pipe.
 18. The method of claim 16, wherein: The running tool is deployed by one of a slickline system, a wireline system, a coil tubing system, or a drill pipe.
 19. The method of claim 15, wherein: the second engagement assembly is at least one of a mechanical, a hydraulic, and an electric activation.
 20. The method of claim 16, wherein: the second engagement assembly is at least one of a mechanical, a hydraulic, and an electric activation. 